Feb 5, 2019
Vallerie McLaughlin, MD gives an overview of 6th World Symposium on Pulmonary Hypertension, which took place in Nice, France, in early 2018. Dr. McLaughlin is the Director of the Pulmonary Hypertension Program at the University of Michigan in Ann Arbor. She is a Fellow of the American College of Cardiology, American College of Chest Physicians, and American Heart Association (AHA). Dr. McLaughlin has been the Principal Investigator of several major clinical trials of drug therapies for pulmonary arterial hypertension and has published numerous papers in this field.
My name is Valerie McLaughlin, I'm a cardiologist at the University of Michigan, and my area of expertise is pulmonary hypertension. I've been doing this for over 20 years and it's been a really remarkable ride.
It's very exciting today to talk to you about some of the latest discussions that occurred at the 6th World Symposium on Pulmonary Hypertension, which took place in Nice, France, in early 2018.
I had the pleasure of attending the symposium and being involved in one of the task forces, and I attended all of the presentations of the task forces. There were 13 task forces at the World Symposium, and it's really a great opportunity for experts in the field to review the literature, make recommendations, not only about how patients should be treated now, but about what things are likely to make an impact in the future.
So, it's important that we secure funding for this. That's probably step one. But then we put together the task force years in advance, and they start working well in advance of the actual meeting. In fact, hopefully, they come to the meeting with a number of documents in place, so that they can talk as a group about what the best recommendations are. After they do that, the recommendations for each of the task forces are presented to the whole population, all of the attendees, and then there is an opportunity for discussion.
After that discussion, we then take into account all of the discussion, all of the perspectives, and then write a manuscript. Those manuscripts get published as a supplement or as a journal, and in this case, it's now published in the European Respiratory Journal.
The first thing that really changed at the World Symposium was the definition of pulmonary hypertension. As you all probably know, pulmonary hypertension is high blood pressure in the lungs. Just like there is a blood pressure in the arm, there is a blood pressure in the lungs too. And sometimes when the blood pressure in the lungs gets elevated, the right side of the heart has a hard time pushing the blood forward, and the patient becomes symptomatic with the most common symptom being shortness of breath.
Many years ago, the cut-off for the definition of pulmonary hypertension was defined as a mean pulmonary artery pressure of greater than 25. That was really decided quite arbitrarily at a conference many, many years ago, but that definition has been carried forward. Over the more recent years, we've learned from studies doing heart catheterizations on patients, including patients who don't have the disease, that the cut-off of 25 may be too high. In fact, the normal population should have a cut-off of no more than 20 for their mean pulmonary pressure. Now that's not the top number, that's the mean pulmonary artery pressure. And this was an area that was discussed in some detail at the World Symposium. After reviewing the data, the definition has now changed.
So [now] to be called pulmonary arterial hypertension, one has to have a mean pulmonary artery pressure of greater than 20, measured at right heart catheterization, with a wedge pressure (or left heart filling pressure) of less than 15 and a calculated pulmonary vascular resistance of greater than 3 Wood units. The pulmonary vascular resistance is a calculated number that takes into account not only the pressure in the pulmonary arteries, but also how the blood flow goes through the heart. So this is the new hemodynamic definition of pulmonary hypertension.
Another important topic that was discussed at the World Symposium was how to treat pulmonary hypertension and what treatment goals should be. We've learned over the years that there are certain factors that can predict how well a patient is going to do. How to assess the risk can be done in multiple different ways. At the World Symposium, we reviewed a number of ways to assess risk, including the REVEAL risk score, the ESC/ERS recommendations (European Society of Cardiology (ESC) and the European Respiratory Society), and a French approach, which is a more simple approach based on how many low risk factors a patient has.
All of these techniques have many things in common; the things that we know predict a better prognosis. Those things include simply how a patient is doing as measured as functional class. The less symptomatic a patient is, the better they do. There are also measures of exercise tolerance; how far a patient walks on a 6 minute hall walk, or how well they exercise on cardio-pulmonary exercise testing. Their symptoms of heart failure, whether or not they have fluid retention. Some hemodynamic markers, like the cardiac output and right atrial pressure. Biomarkers, a simple blood test like BNP. All of these things are important in predicting risk, and of these 3 different techniques, while they measure different things they all have definitions of what a low risk state is.
The data now show that no matter which technique you use to assess risk, if you can get a patient into the low risk status, they're going to do well. So the new treatment algorithm really emphasizes the importance of risk assessment. If you assess a patient at the time of their diagnosis, one needs to start therapy based on how sick they are. Sometimes patients get to us and they're still very, very sick, they're very advanced, and we need to be very aggressive with therapy, and we might start in fact 3 drugs at once including a prostacyclin like an IV or a SubQ therapy. Sometimes they're not quite as sick and we'll start one, or most often two oral therapies.
But really the key in the new treatment algorithm is the reassessment. No matter what you started a patient on, you have to reassess the patient and see if they're at low risk. If they're at low risk after that first treatment choice, that's great. We just continue to follow them and make sure they stay in that low risk category. If they are not meeting the criteria for low risk after the initial treatment choice, one needs to do something differently, whether that's add another medication or whether that's switch a medication, go on to a more aggressive type of a prostacyclin for example. You need to do something differently. They whole goal of the new treatment algorithm is getting the patient into a low risk status.
At the 6th World Symposium, this was the first time that we had a whole task force dedicated to patients' perspective. We'd always been very physician and researcher oriented in the past, and this year we had a task force that included physicians, nurses, patients, patient advocates, patient family members, and representatives from some of the patient organizations, the associations. Their key was really to talk about different things that are important to patients, and they came out with some very important comments that I think we as a medical community need to take into consideration as we plan subsequent meetings, as we take care of patients, and as we plan clinical research trials.
One thing that they discussed in some detail was quality of life. This is something that's very important, and is a little bit difficult at times for scientists to quantitate. When we do clinical trials to get medications approved, we want something very hard. For example, 6 minute hall walk in the earlier trials, or morbidity and mortality in the later trials. While that is a path to FDA approval of agents, the patients want something that really reflects in their everyday life. And so quality of life measures is something that I think we need to consider more strongly as we do further clinical trials. And in fact this year, there was a new quality of life measurement tool called the PAH-SYMPACT. It's simply a quality of life questionnaire, but it was developed with FDA guidance. I think that will be a nice tool to use in subsequent clinical trials.
Another thing that was discussed in the patient perspective task force, was the concept of rolls of the different participants. This is not just a decision that a physician makes, or another practitioner, it's important to emphasize the concept of what we call shared decision making. The patient and the patient's family members have to play an important role as we treat patients. Some of these therapies that we use are quite complex and it requires a huge commitment by the patient and their family member. And they really need to understand the facts of those therapies, the implications of those therapies, and have to balance whether or not those therapies are right for them.
Another point that was made, something that I as a physician struggle with, is the concept of palliative care. We heard from our patients in the patient perspective that they want to know at palliative care. They want to know those options. For me personally, as a physician, I always feel like the patients come to us for hope, the patients come to us to get better, and it takes a lot for me to kind of say, maybe we're not doing as well as we would like and maybe we need to consider alternative options. But what we heard from the patients is they want to understand those other options sooner rather than later. And so I think that it is important to the medical community and the patients, as well, to be proactive about making sure we discuss all options of patient care, and sometimes that includes palliative care.
Thank you for joining me, I'm Valerie McLaughlin from the University of Michigan, and I'm aware that I'm rare.
Learn more about pulmonary hypertension at www.phaware.global Never miss an episode with the phaware® podcast app. Follow us @phaware on Facebook, Twitter, Instagram, YouTube & Linkedin Engage for a cure: www.phaware.global/donate @umichmedicine @umichCVC @antidote_me @accpchest #phaware #phawareMD